G. Tavosanis et al., ESSENTIAL ROLE FOR GAMMA-TUBULIN IN THE ACENTRIOLAR FEMALE MEIOTIC SPINDLE OF DROSOPHILA, EMBO journal, 16(8), 1997, pp. 1809-1819
Microtubule nucleation in vivo requires gamma-tubulin, a highly conser
ved component of microtubule-organizing centers. In Drosophila melanog
aster there are two gamma-tubulin genes, gamma TUB23C and gamma TUB37C
. Here we report the cytological and molecular characterization of the
37C isoform, By Western blotting, this protein can only be detected i
n ovaries and embryos. Antibodies against this isoform predominantly l
abel the centrosomes in embryos from early cleavage divisions until cy
cle 15, but fail to reveal any particular localization of gamma-tubuli
n in the developing egg chambers. The loss of function of this gene re
sults in female sterility and has no effect on viability or male ferti
lity. Early stages of oogenesis are unaffected by mutations in this ge
ne, as judged both by morphological criteria and by localization of re
porter genes, but the female meiotic spindle is extremely disrupted. N
uclear proliferation within the eggs laid by mutant females is also im
paired, We conclude that the expression of the 37C gamma-tubulin isofo
rm of D. melanogaster is under strict developmental regulation and tha
t the organization of the female meiotic spindle requires gamma-tubuli
n.